Three-dimensional (3D) cultures, so-called organoids, have emerged as an attractive tool for disease modeling and therapeutic innovations. Here, we aim to determine if boundary cap neural crest stem cells (BC) can survive and differentiate in gelatin-based 3D bioprinted bioink scaffolds in order to establish an enabling technology for the fabrication of spinal cord organoids on a chip. BC previously demonstrated the ability to support survival and differentiation of co-implanted or co-cultured cells and supported motor neuron survival in excitotoxically challenged spinal cord slice cultures. We tested different combinations of bioink and cross-linked material, analyzed the survival of BC on the surface and inside the scaffolds, and then tested if human iPSC-derived neural cells (motor neuron precursors and astrocytes) can be printed with the same protocol, which was developed for BC. We showed that this protocol is applicable for human cells. Neural differentiation was more prominent in the peripheral compared to central parts of the printed construct, presumably because of easier access to differentiation-promoting factors in the medium. These findings show that the gelatin-based and enzymatically cross-linked hydrogel is a suitable bioink for building a multicellular, bioprinted spinal cord organoid, but that further measures are still required to achieve uniform neural differentiation.

We previously demonstrated that boundary cap neural crest stem cells (BCs) induce the proliferation of beta-cells in vitro, increase survival of pancreatic islets (PIs) in vivo after transplantation, and themselves strongly increase their proliferation capacity after exposure to space conditions. Therefore, we asked if space conditions can induce the proliferation of beta-cells when PIs are alone or together with BCs in free-floating or 3D-printed form. During the MASER 15 sounding rocket experiment, half of the cells were exposed to 6 min of microgravity (µg), whereas another group of cells were kept in 1 g conditions in a centrifuge onboard. The proliferation marker EdU was added to the cells just before the rocket reached µg conditions. The morphological assessment revealed that PIs successfully survived and strongly proliferated, particularly in the free-floating condition, though the fusion of PIs hampered statistical analysis. Proliferation of beta-cells was displayed in 3D-printed islets two weeks after µg exposure, suggesting that the effects of µg may be delayed. Thus, PIs in 3D-printed scaffolds did not fuse, and this preparation is more suitable than free-floating specimens for morphological analysis in µg studies. PIs maintained their increased proliferation capacity for weeks after µg exposure, an effect that may not appear directly, but can emerge after a delay.

Fibrosis, characterized by excessive deposition of scar tissue, leads to the dysfunction of various organs. An urethral stricture, or pathological narrowing of the urethra, is an example of such scarring. The use of human adipose stem cell conditioned medium (HASC-CM) has shown promise as an anti-fibrotic treatment in vivo, as molecules produced by HASCs exhibit anti-inflammatory and fibrosis-modulating properties. However, HASC-CM has also been demonstrated to activate epithelial-to-mesenchymal transition (EMT) in cancer-associated cells. To elucidate whether HASC-CM promotes EMT or myofibroblast activation, we investigated its effects on primary human urethral fibroblasts (HUFs) and prostatic fibroblasts of the WPMY-1 line. We showed that HASC-CM promotes migration speed in HUFs but not in WPMY-1 cells while also increasing vimentin levels in the cells, both markers of EMT. Moreover, HASC-CM suppressed SMAD5 signalling in HUFs without altering SMAD3 signalling in either cell type. In addition, HASC-CM treatment induced myocardin-related transcription factor A (MRTF-A) nuclear translocation and increased amount of alpha smooth muscle actin (αSMA) in HUFs, indicating a shift towards the myofibroblast phenotype. We conclude that the effect of HASC-CM on WPMY-1 cells is negligible, however, this type of treatment has a pro-fibrotic and EMT-stimulating effect on HUFs.

Introduction: congenital ureteral stenosis is one of the leading causes of impaired urinary drainage and subsequent dilatation of urinary collecting system, known as hydronephrosis or ureterohy-dronephrosis. Mechanism that leads to obstruction is not clearly known. Multiple studies in rat models have shown increased angiotensin 11 and TGFβ levels in obstructed ureteral tissue. The aim of the study is to investigate expression of fibrosis related genes in obstructive and normal ureteral tissue. Material and methods: it is a monocentric study in which nineteen patients were selected prospec-tively. 17 patients of which underwent Hynes-Anderson pyeloplasty due to the PUJO, 2 patients underwent ureteroneocystostomy due to ureterovesical junction obstruction (UVJO) and 6 patients were chosen for control group: 5 underwent nephrectomies due to the kidney tumor and 1- upper pole heminephrectomy due to the duplex kidney with normal pyeloureteric junctions in all. Tissue RNA was chemically extracted after freezing the biopsy samples in liquid nitrogen, with cDNA synthesis performed immediately after nucleic acid isolation. qPCR to evaluate the relative expres-sion of Tgfb1, Mmp1, Timp1, Pai1, Ctgf and Vegfa was performed. Expression levels of Gapdh and Gpi genes (geometric average) were used to calculate the relative expression of the investigated genes. Outliers were removed prior to calculating confidence intervals for the experimental groups, and Wilcoxon rank-sum test was performed to determine statistical significance of the differences. Results: significant differences between healthy and stenotic tissue samples in Ctgf gene expression levels were observed, with the samples from afflicted tissue showing lower expression. No statistical difference in expression levels of Tgfb1, Timp1, Vegfa, Mmp1, Pai1 was found. Discussion and conclusions: These findings suggest that tissue fibrosis similar to other tissues and organs is not the leading cause of stenosis, at least at the moment of surgery. Decreased CTGF ex-pression is indicative of developmental origin of obstruction.